Screw holding device



Nov. 7, 1933'. P. L. STENMAN SCREW HOLDING DEVICE Filed July 28. 1931manetic force the blanks re held in the correct so arranged, that themagnetic power holds the 65 move the worked blank and partly when a newblank.

'20 holding the blank during the operation. prevent the head of thescrew blank from passing ?5 3 5 movement regulates the jaws. Thiscontrolling O t departing from the 1 of the a s- 90 Patented Nov. 7,1933' I j 1,934,568 soREw HOLDING DEVICE Per Leonard Stenrnan,Stockholm, Sweden, as-

signor to Ak'tiebolage't Traskruv, Stockholm, Sweol'ema corporation 7Application July 28, 1931, Serial No. 553,6l1,"anol inSweden August 15,1930 7 s Claims. (o1. 10-107;

This invention'refers to a device with a methrough'electric current forholding the blanks in chanical arrangement for holding screw blanks, theproper position. whereby two or more jaws are arranged at the It isadvantageous that the jaws close half way 7 one end of the device andwhich in addition has or partly so that the head of the blank gets a 5 apipe or groove, through which a magnetic rod rest against or issupported by the half closed so (or a rod magnetized throughelectricalcurrent jaws, untilthese finally close around the blank or a rodmagnetized through one or several p'er for holding the same during themachining opmanent magnets or also any other pushing device) eration. Vinserts the blanks between the jaws. Through The feeding of the screwblanks can also be position relative to the jaws. The movement of blankso'strongly-against the pushing device, that these jaws is arranged insuch a way, that they the blank receives a fixed correct positionrelacan partly hold the prepared blank during the tive .to the jaws,which from fully opened posi-. I continued operation and thereafter opento retion can close in one operation for holding the ((0 blank is movedinto working position with the' The feeding of the blank'can also be soaraid of a pushing device half close or contract so ranged, that thepushing devicev 6 without being that the head of the following blank isprevented ma ne c, feeds the blanks to the laws, which from passingthrough, then to close again for have half closed from full opening inorder to The drawing shows one form of device for between the jaws 1 andthereafter close for holdcarrying out the invention. ing the blank.

Fig. 1 shows a lengthwise section through the The ma ne d Which y be anholding device with its pushing devices ready for El ct 1 8, can eitherbe Placed aTOuIldOI' the moving of the blank through the same, outsideof the holding device. The invention can Fig. 2 shows an end View partlyin transverse eithe be C ns u t on i Su a Way that t section and Figs. 3and 4 show respectively similar holding device rotates with the blankheld therelengthwise sections as Fig. 1 through the holding in and the'threadcutting tools are at a rest or device with different positions ofthe jaws and t holding device can be t a Test a t e 30 the pushing rod.cutting tools rotate, as is well known, whereby Fig. 1 shows the holdingde i e ith l ed the relative motion between the parts of the jaws 1,whereby for instance a fork 2 or some holding device remains the same asabove deother controlling device, moved by a cam 3, or scribed; and itwill be obvious that the details other mechanical arrangement i hi h thof the invention can be otherwise varied withdevice is so arranged, thatthe same at different The electromagnetic coil 8 surrounds the tube 7positions relative to the fork 2 partly eifectuates d v enclosed aCasing 9 Which has d the opening of the jaws in order to let the screwto it a gea 10 f ot t the Ca a d head 4 pass, partly hereafter. close tosuch an the tube 7. This rotating. structure is mounted n extent thatthe head of the following blank is .on roller'b arin 11, nd the c rrenis supplied; prevented from passing and at last press the to the coilthrough the medium of contact rings jaws together for holding the blank4 during the 12 and brushes 13. According to another emmachiningoperation. The jaws 1 are pivotally bodim nt th oil do s not p rf rm nym v mounted through the medium of pivots 21 supment. This constructionis more favorable and 45 ported in ring 15 hereinafter described. 'morereliable, as rotating contact rings and The movement of the closing ofthe jaws is other similar devices are unnecessary. eifected through theabove mentioned fork 2, Mounted and rotating with the coil, or acwhichworks a ring 5 according to the drawing cording to the other embodimentsuggested, or also directly or in some other way engages the around thecoil'casing 9 is a pair of arms 14 50 device, regulating the jaws. Theback and forth which enter a ring 15 (rotatable on a ball bearmovablepushing device 6 feeds the screw blanks ing 16) and carry on their outerends antifricthrough a tube 7 or a groove in the holding device tionrollers 17. Y The outer surfaces of the jaws to the jaws. 1 arecam-faced in such manner that when the This pushing device can forinstance consist arms 14 move by means of the aforesaid fork 55 of arod, which is magnetic or magnetized 2 to their extreme forward positionthe jaws 11 heretofore stated.

will be closed tightly upon the blank to hold it while it is beingthreaded. When the arms 14 are by means of the fork 2 moved in theopposite direction into their extreme back position, the jaws 1 willopen wide as shown in Fig. 3 to thus free the blank; the jaws bycentrifugal force but to insure'their proper opening in all emergencies,the tail end 19 of the cam engages inwardly-extending lugs 20 on theparts 14. And when the arms 14 are moved forwardly to near their extremeforward position, the cam faces 18 are so shaped that the jaws will bepartly closed, as shown in Fig. 4, ready toreceive the blank as it ispushed forwardly by the pusher rod 6; then the arms 14 continue to moveforwardly so as I claim: 7 1. In an apparatus for making screws, a chuckstructure embodying a pair of jaws, means for pushing the blanksendwisely into said jaws,

through and to receive will openautomatically' for pushing blanks intoto clamp the blank, as

and cam devices for first partly closing the jaws to permit the shank ofthe blank to pass there- 7 and stop the head of the shank to prevent theblank being pushed out of the jaws, then clamping the blank to hold itrigidly while it is being threaded, and then opening the jaws to theirfull extent to thus release the blank after it is threaded.

2. The structure recited in claim 1, said means the chuck consisting ofa rod made magnetic at the point where it contacts with the blank headto thus magnetically attract the blank head and hold the blank centrallywith respect jaw whilethe blank is being inserted therein.

3. The structure recited in claim 1, said cam devices consisting of camfaces formed on the outer faces of the jaws and cooperating with deviceslocated outside of the jaws and moved back and forth with respectthereto.

PER LEONARD STENMAN.

to the gripping parts of the

